urine is formed by the three steps...
Filtration
Reabsorbtion
Secretion

what is the difference between reabsorbtion and secretion ?

My though: The difference is that reabsorbtion is the movement of essential molecules rom the nephrons to the blood. Where as secretion is the movement of ammonia and other durgs or substances that the blody is trying to get rid of, from the blood to the nephrons.

Pick your explanation:
1. The act or process of augmenting, or making larger, by addition, expansion, or dilation; increase.

2. The state of being augmented; enlargement.

3. The thing added by way of enlargement.

4. A additional charge to a coat of arms, given as a mark of honor.

5. (Science: medicine) The stage of a disease in which the symptoms go on increasing.

6. In counterpoint and fugue, a repetition of the subject in tones of twice the original length. Augmentation court, a court erected by Stat. 27 Hen. VIII, to augment to revenues of the crown by the suppression of monasteries. It was long ago dissolved.